Big Creek Rare II Study Area

The Big Creek Rare II Study Area encompasses 9,277 acres of hilly terrain across the Mark Twain National Forest in Missouri, where seven named hollows—Gray, Smith, Tennyson, Terry, Buttram, Pet, and Short—drain toward the East Fork and West Fork Big Creek watersheds. Elevations range from 740 feet in Smith Hollow to 898 feet in Terry Hollow, creating a landscape of moderate relief where water moves through limestone and dolomite substrates. These headwater drainages form the hydrologic foundation of the Big Creek system, with seepage and seasonal flow shaping the character of each hollow and the riparian corridors that follow them downstream.

The area supports a mosaic of distinct forest and woodland communities shaped by underlying geology and moisture availability. Dolomite Glades and Limestone/Dolomite Savannas occupy the driest, most exposed sites, where American smoketree (Cotinus obovatus), post oak (Quercus stellata), and chinquapin oak (Quercus muehlenbergii) form open canopies above a diverse herbaceous layer. Yellow coneflower (Echinacea paradoxa), Missouri bladderpod (Physaria filiformis), threatened under the Endangered Species Act, and big bluestem (Andropogon gerardii) dominate the ground layer in these sun-exposed communities. Ozark Cherty Woodlands occupy intermediate sites with similar oak dominance but denser understory structure. In the moister hollows and riparian zones, Riparian Forest develops with Carolina buckthorn (Frangula caroliniana) and lowbush blueberry (Vaccinium pallidum) in the understory, along with aromatic sumac (Rhus aromatica) and New Jersey tea (Ceanothus americanus). Mead's sedge (Carex meadii) and sideoats grama (Bouteloua curtipendula) persist in the herbaceous layer across multiple community types.

The area supports three federally endangered bat species—the gray bat (Myotis grisescens), Indiana bat (Myotis sodalis), and Northern Long-Eared Bat (Myotis septentrionalis)—that roost in caves and hollow trees within and near the study area, emerging at dusk to forage over the hollows and along riparian corridors. The tricolored bat (Perimyotis subflavus), proposed for federal endangered status, hunts the same airspace. Reptiles and amphibians occupy distinct microhabitats: Eastern Collared Lizards (Crotaphytus collaris) and Prairie Lizards (Sceloporus consobrinus) bask on exposed rock and bare ground in the glades, while Three-toed Box Turtles (Terrapene triunguis), near threatened (IUCN), move through leaf litter in the woodlands. Pickerel Frogs (Lithobates palustris) breed in the seepage areas and shallow pools of the hollows, and the alligator snapping turtle (Macrochelys temminckii), proposed for federal threatened status, inhabits the deeper pools and creek channels. Monarch butterflies (Danaus plexippus), proposed for federal threatened status, migrate through the area in spring and fall, using native milkweed and other nectar sources in the open communities. Yellow-breasted Chats (Icteria virens) and Indigo Buntings (Passerina cyanea) breed in the shrubby understory of the woodlands and savannas.

Walking through the Big Creek area, a visitor experiences sharp transitions between ecological communities. Ascending from a hollow bottom where Riparian Forest crowds the streamside, the forest opens into Ozark Cherty Woodland, where the canopy thins and light reaches the ground layer. Continuing upslope, the woodland grades into Dolomite Glade or Limestone/Dolomite Savanna, where the canopy breaks into scattered trees and the landscape opens to sky. Here, the ground is visible—bare dolomite, sparse grass, and low herbaceous plants—and the air warms noticeably. The sound of water recedes as elevation increases. Moving along a ridge or across a glade, the visual field expands; in spring and summer, the yellow flowers of coneflower and the vertical stems of big bluestem mark the herbaceous layer. Descending again into a hollow, the forest closes in, shade deepens, and the sound of seepage or flowing water returns. The shift from open glade to closed forest, repeated across the seven hollows, defines the rhythm of movement through this landscape.

The area that is now Big Creek Rare II Study Area was historically inhabited by the Osage and other Native American groups who used fire to manage the landscape, maintaining open oak woodlands and glades across the region.

Between the 1870s and 1920s, the landscape underwent intensive logging of native oak, hickory, and shortleaf pine. The Ozark Land and Lumber Company and other operators employed temporary narrow-gauge railroads, called tramways, to transport logs from remote hollows to central mills. Large timber operations established temporary company towns and boarding houses, some accommodating up to 150 workers during peak logging years. By the 1920s, much of the native forest in southern Missouri had been stripped, leaving extensive areas idle and abandoned.

Following the timber boom, many areas were converted to pasture or tilled for agriculture. However, the thin Ozark soils were frequently over-used, resulting in serious erosion and diminished productivity. In response to these conditions, the federal government began acquiring the degraded forestlands starting in 1933–1934 under authority of the Weeks Act of 1911, which permitted the purchase of private land to protect the headwaters of rivers and streams.

During the 1930s, the Civilian Conservation Corps rehabilitated the acquired lands through reforestation efforts, road construction, and the building of ranger stations, including the nearby Ava Ranger Station. In 1962, President John F. Kennedy signed Executive Order 11028 to transfer specific lands between the Clark and Mark Twain National Forests to improve administrative efficiency. The area was designated as a Roadless Area Review and Evaluation (RARE II) study area in the late 1970s to assess its eligibility for formal Wilderness designation under the Wilderness Act of 1964. The Big Creek Rare II Study Area is now an Inventoried Roadless Area protected under the 2001 Roadless Area Conservation Rule.

Vital Resources Protected

Headwater Bat Refugia in Interior Forest The Big Creek area's unfragmented upland and riparian forest provides critical summer roosting habitat for three federally endangered bat species: the Indiana bat (Myotis sodalis), Northern Long-eared bat (Myotis septentrionalis), and gray bat (Myotis grisescens). These bats depend on mature trees with loose bark for daytime shelter during the breeding season. Road construction fragments interior forest, removes mature trees, and creates edge habitat where predators and parasites are more active—directly reducing the secure roosting sites these species require to survive and reproduce in the Ozarks.

Karst Aquatic Connectivity and Salamander Habitat The Big Creek drainage's limestone and dolomite geology creates a network of springs, seeps, and cave-fed streams that support specialized species like the grotto salamander (Eurycea spelaea). This karst hydrology is exceptionally sensitive to surface disturbance: road construction on hillslopes increases sedimentation and alters groundwater flow patterns, which degrades the clear, cool, sediment-free conditions that cave-dependent salamanders require. Once sedimentation fills spawning substrates and clogs spring outflows, these populations cannot recover without decades of natural sediment flushing.

Native Glade and Woodland Flora in Shallow-Soil Ecosystems The dolomite glades and oak woodlands scattered across the Big Creek hollows support rare plants including Missouri bladderpod (Physaria filiformis, federally threatened), yellow coneflower (Echinacea paradoxa, G3 rarity), and Fremont's leather flower (Clematis fremontii, state vulnerable). These species occupy thin-soil, rocky microsites that are easily destroyed by road cuts and fill. Road construction also opens corridors for invasive species like Sericha lespedeza and Tree of Heaven, which outcompete native wildflowers and prevent the oak regeneration these glades depend on.

Riparian Forest Canopy and Water Temperature Regulation The riparian forests along the East Fork and West Fork Big Creek headwaters shade the stream network and regulate water temperature—critical for the alligator snapping turtle (Macrochelys temminckii, proposed threatened) and native aquatic communities. Road construction removes streamside trees through clearing and fill, exposing water to direct sunlight. This increases stream temperature, reduces dissolved oxygen, and degrades habitat for cold-water-dependent species. The Big Creek watershed is already rated "Functioning at Risk" due to sedimentation and fragmentation; canopy loss from roadside clearing would accelerate this decline.

Threats from Road Construction

Sedimentation of Karst Drainage Network from Cut Slopes and Fills Road construction on the hilly terrain of Big Creek requires cutting into slopes and creating fills across hollows. These exposed soil surfaces erode during the frequent precipitation events predicted to increase with climate change, sending sediment into the drainage network. The Big Creek watershed is already impaired for sedimentation and siltation on the EPA 303(d) list; road-derived sediment would further degrade spawning substrates for aquatic species and fill the clear spring outflows that grotto salamanders depend on. Unlike erosion from dispersed use, road-generated sedimentation is chronic and concentrated, making recovery impossible without road removal.

Habitat Fragmentation and Loss of Interior Forest Conditions for Bat Roosting Road construction divides the unfragmented interior forest into smaller patches, creating edge habitat where temperature fluctuations, predators, and parasites are more prevalent. Indiana bats and Northern Long-eared bats require large, continuous forest blocks to find sufficient mature roosting trees and insect prey. Fragmentation also increases exposure to White-nose Syndrome transmission, as bats at forest edges are more likely to encounter infected individuals. Once interior forest is fragmented by roads, the ecological conditions that make this area suitable for endangered bat populations are lost—these species cannot recolonize fragmented habitat even if the road is later closed.

Invasive Species Establishment Along Road Corridors Road construction creates disturbed soil and exposed mineral substrate that invasive plants exploit. Sericea lespedeza and Tree of Heaven spread rapidly along road edges and into adjacent forest, outcompeting the native oak-hickory regeneration and wildflowers that support the area's rare plant communities. Road maintenance and vehicle traffic also disperse invasive seeds and feral hog populations, which cause severe soil erosion and destroy native ground flora. Once established, these invasives persist indefinitely and prevent restoration of native glade and woodland ecosystems.

Stream Temperature Increase from Canopy Removal and Riparian Clearing Road construction through riparian zones requires removal of streamside trees for clearing and fill placement. Loss of this canopy shade causes stream temperature to rise, reducing dissolved oxygen and degrading habitat for cold-water species including the alligator snapping turtle and native aquatic communities already stressed by sedimentation. The Big Creek headwaters are particularly vulnerable because they are small, high-gradient streams with limited buffering capacity—even partial canopy loss causes measurable temperature increases that persist for years. Riparian forest recovery is slow in the Ozarks, making this impact effectively permanent on ecological timescales.

The Big Creek Rare II Study Area encompasses 9,277 acres of hilly Ozark woodland in the Mark Twain National Forest, centered on the Big Creek drainage basin. The area's network of hollows—Gray, Smith, Tennyson, Terry, Buttram, Pet, and Short—drains into Big Creek, a spring-fed stream that flows north toward the St. Francis River. The roadless condition of this basin preserves the quiet, undisturbed character essential to the recreation opportunities described below.

Hunting is a primary use in the Big Creek Basin. White-tailed deer and wild turkey are common in the oak woodland habitat, and the area is managed as a Walk-in Turkey Hunting Area during spring season, offering remote hunting away from motorized traffic. Small game includes raccoon, bobcat, fox, coyote, and southern flying squirrel in the riparian forest and woodland edges. Northern bobwhite quail and mourning dove are present in the broader forest context. Portable deer stands are permitted but must be removed by February 1st. Access is via Highway A409 from Ava (south on Highway 5, west on Highway A to Smallett Junction, then south on A409; the Big Creek area lies approximately 2 miles past the junction of FR 147 and A409). The Forest Service actively restores the basin through thinning and prescribed fire on a three-year rotation to maintain open woodland structure—management that directly improves habitat for deer and turkey. The roadless designation ensures that hunting here remains a dispersed, non-motorized experience; off-road vehicle use is restricted to numbered forest roads.

Fishing opportunities center on Big Creek itself, a high-quality Ozark headwaters stream designated as an Outstanding State Resource Water by Missouri. The stream supports smallmouth bass, largemouth bass, spotted bass, Ozark bass, crappie, catfish, and other species common to the White River watershed. Big Creek is critical habitat for the federally threatened Big Creek crayfish (Faxonius peruncus), and anglers should be aware of a "Do Not Eat" advisory for sunfish caught near Glover due to historic lead contamination. Access to Big Creek is available at a pull-off on Highway A409 (approximately 2 miles from the FR 147 junction), where the stream is readily reached on foot. Interior access to the stream requires non-motorized travel from the roadless area's periphery, preserving the undisturbed riparian forest and cold-water habitat that support both the fishery and the threatened crayfish population.

Birding in the Big Creek Basin takes advantage of the area's restored oak woodland and glade habitats. Scarlet Tanager, Red-headed Woodpecker, Wild Turkey, Whip-poor-will, and Cooper's Hawk are documented woodland species. Indigo Bunting is present in the area. Spring is peak season for migratory songbirds and breeding activity. The Glade Top National Scenic Byway (Highway A409) provides a ridge-top viewpoint over the basin where restored glade and woodland habitats support diverse bird communities. The area's active management—thinning and prescribed fire to maintain open canopy and diverse ground cover—directly supports the species composition that makes birding productive here. The roadless condition ensures that interior birding remains a quiet, non-motorized experience.

Paddling on Big Creek is a seasonal activity dependent on adequate water flow. Big Creek is generally Class II, with sections reaching Class I–III in most runnable stages and potentially Class IV–V during high water. The creek features shut-ins (narrow canyons with boulder gardens) that create technical rapids. Paddling is limited to spring and early summer or immediately after heavy rainfall; a minimum of 50 cfs is required for kayaks, and paddlers recommend at least 2 feet on the local gauge to minimize portaging. Access points include the Iron County Road 163 Ford (approximately 1/2 mile from Highway 143), used for a 7-mile float to Sam A. Baker State Park. The roadless condition preserves the riparian forest corridor and undisturbed streambed that define the paddling experience on Big Creek.

Photography opportunities include scenic views from the Glade Top National Scenic Byway (Highway A409), which overlooks the Big Creek Basin and restored oak woodland and glade habitats. Spring wildflowers bloom in riparian forests during March and April; glade wildflowers peak in June and July. American smoketree, yellow coneflower, and Missouri bladderpod are documented botanical features. Wildlife photography subjects include songbirds, wild turkeys, white-tailed deer, and pollinators in restored glade and woodland habitats. The area is noted for dark skies and stargazing opportunities. The roadless designation preserves the open, undisturbed landscape that makes these scenic and wildlife photography experiences possible.